1. Field of the Invention
The present invention relates to a gas passage structure in a compressor in which a compression operating body is moved by the rotation of a rotating shaft, a gas flow control valve, that controls the gas flow in a gas passage within a main body of the compressor that compresses and discharges gas by means of the action of the compression operating body, is provided, and the gas flow control valve is attached to the main body of the compressor so as to oppose a gas passage forming body that forms the gas passage.
2. Description of the Related Art
In a compressor of variable displacement type such as that disclosed in Japanese Unexamined Patent Publication (Kokai) No. 6-336978, refrigerant is supplied from a discharge chamber to a crank chamber and, at the same time, is discharged from the crank chamber to a suction chamber to control the pressure in the crank chamber, and displacement control is carried out in a manner that the inclination of a swash plate is increased by a pressure drop in the crank chamber and decreased by a pressure increase in the crank chamber. The refrigerant in the discharge chamber is sent to the crank chamber through a supply passage and the refrigerant in the crank chamber flows into the suction chamber through a bleed passage. A control valve is interposed in the supply passage. The control valve controls the flow rate of the refrigerant sent from the discharge chamber to the crank chamber.
The control valve is attached to a rear housing that forms the discharge chamber and the suction chamber, and a part of the control valve is exposed on the outside of the compressor. In this structure, in which part of the control valve is exposed, it is necessary to prevent the refrigerant in the compressor from leaking out, through the coupling surface between the control valve and the rear housing, to the outer side of the compressor. It is also necessary to prevent the supply passage that runs from the control valve to the discharge chamber and the supply passage that runs from the control valve to the crank chamber from communicating with each other through the coupling surface. Therefore, plural ring shaped seal members are interposed between the outer surface of the control valve and the rear housing.
However, the structure, in which plural seal members of ring shape are interposed between the outer surface of the control valve and the rear housing, makes the work of assembling a compressor equipped with the control valve intricate. Moreover, if the number of seal members is increased, the cost of the compressor is also increased.
The seal members described above are made of rubber and a seal member, deformed elastically between the outer surface of the control valve and the rear housing, prevents the refrigerant from leaking. When carbon dioxide is used as refrigerant, it is used at a pressure higher than that when a chlorofluorocarbon-type refrigerant is used, and carbon dioxide at high pressure can easily permeate the inner side of the rubber seal member. If the carbon dioxide at high pressure permeates the inner side of the rubber seal member while the compressor is in operation and the pressure of the carbon dioxide drops when the operation of the compressor is terminated, the carbon dioxide that has permeated the inner side of the seal member expands. A foaming phenomenon, in which the carbon dioxide in the inner side of the seal member expands, damages the rubber seal member. The damage to the seal member causes the sealing performance of the seal member to degrade. Therefore, malfunctions, in that part of the refrigerant to be sent to the crank chamber leaks out of the compressor or that the refrigerant is sent to the crank chamber excessively, are caused. If the refrigerant leaks out of the compressor, the quantity of the refrigerant runs low and the efficiency of the compressor is degraded. If the refrigerant is sent to the crank chamber excessively, a stable displacement control is impeded.
The first object of the present invention is to reduce the number of the seal members relating to the gas flow control valve that controls the gas flow in the gas passage within the main body of the compressor. The second object of the present invention is to prevent an abnormal gas flow due to the damage of the seal members.
Therefore, the present invention applies to a compressor, in which a gas transfer body is moved by the rotation of the rotating shaft, gases are transferred by the action of the gas transfer body, and a gas flow control valve that controls the gas flow in the gas passage within the compressor is provided. In the first aspect of the present invention, a seal means that is formed by one seal member or plural seal members is interposed between installing surfaces, opposing the gas flow control valve, on the gas passage forming body side, and installing surfaces, opposing the gas passage forming body, on the gas flow control valve side, a first gas passage that passes within the gas passage forming body is connected to an inner valve port of the gas flow control valve, a second gas passage that passes within the gas passage forming body is connected to the valve port of the gas flow control valve so that the second gas passage is communicated with the first gas passage via the valve port, the first gas passage and the second gas passage are penetrated through each of the opposing installing surfaces within the surrounded area on each of the opposing installing surfaces surrounded by seal operating portions of the one or plural seal members, and at least either the first gas passage or the second gas passage penetrates through the seal operating portions of the one or plural seal members.
Both the first gas passage and the second gas passage are prevented from communicating with the outer side of the compressor via the opposing installing surfaces by the seal operating portions of the one or plural seal members. Therefore, the gas in the first gas passage and that in the second passage do not leak out of the compressor. The first gas passage and the second gas passage are prevented from communication with each other via the opposing installing surfaces by the seal operating portions of the one or plural seal members. Therefore, the first gas passage and the second gas passage are communicated with each other only via the valve port. In the structure in which at least either the first gas passage or the second gas passage penetrates through the seal member, the prevention of communication between the first gas passage and the outside of the compressor, between the second gas passage and the outside of the compressor, and between the first gas passage and the second gas passage can be achieved by the single seal member.
In another embodiment of the present invention, the compressor of the first embodiment of the present invention is modified into a compressor of a variable displacement type, comprising a swash plate contained in a control pressure chamber so that integral rotation with the rotating shaft is allowed and the inclination angle, with respect to the rotating shaft, can be varied, and plural pistons, which are arranged around the rotating shaft and perform reciprocating motion in accordance with the inclination angle of the swash plate, wherein: gas is supplied from a discharge pressure area to the control pressure chamber via a pressure supply passage; gas is released from the control pressure chamber to a suction pressure area via a pressure release passage to control the pressure in the control pressure chamber; the inclination angle of the swash plate is increased by a pressure drop in the control pressure chamber and the inclination angle of the swash plate is decreased by a pressure increase in the control pressure chamber; and the gas flow control valve controls the gas flow in the pressure supply passage or the gas flow in the pressure release passage.
The present invention can be appropriately applied to the gas flow control valve which controls the displacement of the compressor of variable displacement type.
The present invention may be more fully understood from the description of the preferred embodiments of the invention set forth below, together with the accompanying drawings.